Molding machine



April 27, 1948. D, CRQPP 2,440,367 T MOLDING MACHINE 7 Filed Jul 24, 1945 2 Sheets-Sheet 1 Fig.1

David Cropp April 27, 1948. D, ROPP 2,440,367

MOLDING MACHINE Filed July 24, 1945 2 Sheets-Sheet 2 oo o 3 3M ""1 David Cro Pp Patented Apr. 27, 1948 MOLDIIf fEiZCHINE E g neering Corporation;

poration of Delaware Application Jll1y24, 1945'," s'e'riali'Nm 606L826v s'claims. (01:18:20)

in en on re te me hineiq m re n plastic materials, andparticul-arly to a; machine of the turret type adapted for automaticsequenl'p er ie a In t m ld n o arge u i e o Small plastioarticles, it is necessary, at least from the cost, to provide all possible means to improvements ina standpoint of yhie o 're de r rem n a hi e e t ut wi ret n-=, It is; -smm enew WY- 99 emv mew: erw qmt eel filling the cavity oi ainold and for closingand opening the mold elementsperiodically as required. There are-of course, many small mol dedarticles which present no. problem in their removal from these mold cavities, However, there areother types of small articles Whih,= being formed with slight undercuts, threads,etc., presentla rather serious pifololeniof remova1' from a mold}, It is with. this latter t'ype of; molded, articles that the present invention is morejpar-ticularly concerned.

, For purposes of illustration, the present invention is shown as constituting. part of an automati'c, sequentially operated; turret typemachine for the compression molding. of internally threaded' bottle capslthe. machine bei g substantially of the type'shown and described inmy co-pending application, Serial N O. 604,762, f1led J11ly 13, 1 945.

theautoinatic sequential molding" of articles oi this type some meansis required to loosen each molded piece, preparatory to the removal of the piece from thecavity in which it has been molded. The tendency of the moldedpice'to adhere to the mold force or cavity Walls islperha'ps greater, and certainly more troublesome to overcome in the caseof articles having rilos,v projections, or threads; To illii'stra;t,. an internally threaded bottle cap may not' merely be pried loose or removed. by some conventional mechanism, but mustfirs't be freediof its tendency to adhere to the'force, and. subsequently unscrewed from the threads of the force. In thespresent invention, mechanism is provided for this purpose, and it is" therefore a purpos'eand object of the invention to provide means Ioy which. small molded articles maybe removed from each moldof an autoinatic'sequential noldingsmachine. It is also an. object of the invention to provide means for looseningla molded article from-the mold element on, or in which it has. been termed. Additionally, it is an object of the invention to provide means for breaking theseal or adherence'of a, molded article'toits mold element prior to the separation of the elements ofthe moid whichseparation is, oi course, preparatory to removlaliof the article.

molding articles from Warren, Pa., a cor 2" Other ohjeots andadvantages.willbe,inoie'fully understood fro lii' a: G iiSideratiQn. of the following specification, taken' inconjunotion withv the ac 'coinpanying drawings; an'din'which. d V Fig, l i's r-mgmepbary front elevanonaiview of automatic sequentiallturret type molding machine embodying one iorm of the invention; and for purposes of illustration shows several of thenioiding units invarious opened. or closed positions} v r U I v ,v i r .Fig. 2 is an enlargidlfragmentary. front elevatiqiiai view" of one ofthe evemigmoiamg, units shown in Fig. ,1, theieleinents'i of. the moidibeing i i-fully closed position, and parts'being broken away to-show ,certainlst'ruetural details;

Fig. 3 is a. fragmentary from. elevationarview of theniolding'unit nqwn n mg, 2, certain parts having' b'e'en' relatively. adjusted preparatory to separation of, the m nd; lements}; 7 Figi 4.15" a sfraementary fiont elevational View of the structure on Fig; ,z witntne elements of the mbm ii iys'epa rezt additional" partsbeing broken away tosiiow structural details} Figs; 5 an s are horizontal sectionaiflviews invention isassociated. Thi's'presscomprisesi two parts, namely aturret fl and a; base- 2. Th'e turret H ispi'eferablyniounted in any wen known mariner? oii'a' central support carriedby the base 1-2, and suitable m chanism is provided for the purpose of rotating the turret at any desired spleedi For b f O fi t r nvention; i may be? s i vth fiit e fi-ee s em y di roma ne. turret i sett'o operate re speed"; con sistent' with nioldingf ,cycle for moldingpieces f the naf iezhnemsjeroui, y s

v The base. 11,, includes a: circumferentiaijtrack is; which; n thelpr'esent showing, is supported on the nedestal portion or, the base: by uprights it. This tracks in a; nonzcntal plane throughputa substantial portibn of its'length, the only break being at the'front of the machine, as. shown in we: of the dr wings, For clearer understandingofthis structure, thermoldi'ng cycle is indicated as comnie'ncingwith the vertical portion' is" and inclined portion 11 of the tracl; l3. On the completion of the molding cyQleQthetrack i i l f s'dbw iz rd n s-in ic ted at l8 and thro g a; part of the length of this incline an upper guard I9 is provided, being supported in any suitable manner, as by parts 2|. Between the end of the incline l8 and the vertical portion I6, the track continues along a horizontal plane 22, substantially as shown. The portion 22 of the track represents a time period between the end of a cycle and the beginning of another cycle and is sufiicient to permit ejecting a molded piece and refilling the mold cavity preparatory to molding another piece.

In the upper portion 23 of the turret there is located a plurality of radially disposed brackets or mold element supports 24 which include upper and lower offset portions 25 and 30, adapted to mount the upper element 26 and lower element 21 of a complete mold. Sufficient space is provided for movement of one of the mold elements into an opened position such that a finished article may be removed. The lower mold element 21, in the present showing of the invention, includes a mold cavity 28, whereas the element 26 is formed with a force 29 on which threads 3| are formed. It will be understood that the element 26, once secured, remains stationary, whereas the element 21 is intended to be movable into an opened or closed position, such as shown by comparison of Figs. 2 and 4 of the drawings.

The ofiset 30 of each support 24 includes a depending sleeve 32. A shaft 33, extending downwardly from the element 21, projects through this offset and sleeve. The lower end 34 of this shaft, in the position shown in Fig. 4, extends beyond the end of the sleeve 32. This end of the shaft is formed with a cylindrical opening 35, into which a rod 36 is adapted to project. The rod 36 does not extend the full depth of the opening 35, and thus space is provided for a coiled spring 31. Adjacent one end the rod 36 is formed with diametrically opposite fiat surfaces 38, and a transverse openingtherethrough accommodates a pin 39. The ends of this pin extend sufficiently beyond the surfaces 38 to mount rollers 4|. These rollers are located in inclined slots 42, formed in that portion of shaft 33 in which ,theopening 35 is made. The slots 42 of any given shaft are reversely inclined and, consequently, any lengthwise movement as between shaft 33 and rod 36 produces relative rotation to an extent determined by the length and incline of the slots 42 in which the rollers 4| are movable.

Joined to, or formed integral with the lower end of the rod 36 is a portion 43, having a transversely apertured end 44. A yoke 46 is pivotally joined along its arms 41 to the end 43 of the rod by a pin 48. .The base of the yoke includes a downwardly extending collar 49. A suitable opening is made through the yoke in which to receive a rod The upper end of this latter, rod is formed with a head 52 that is located between the arms 41, the head being of sufiicient size to prevent displacement of the rod 5|. Adjacent its other end, rod 5| is formed with a threaded portion 53. A nut 54, engaged with the threaded portion 53, adjustably supports a washer-like plate 56. This plate in turn provides a seat for one end of a coiled spring 51 that encircles the rod 5| and has its other end engaged with the under edge of the yoke 46 and surrounds collar 49. Tension of spring 51 may be varied as required by adjustment of the nut 54 over the extensive threaded portion 53. Sufficient spac is, of course, provided between the upper surface of the rod head 52 and the lower edge of the end 44 to assure full use of the spring as the force by which to close the mold elements and hold them in closed position under 4 predetermined pressure during a molding cycle.

Adjacent the threaded portion 53, the rod 5| projects into the base portion of a downwardly opening yoke 58. Yoke and rod are held against relative movement in any suitable manner, as through the use of a drive pin (not shown). The arms 59 of the yoke 58 are apertured to mount a pin 6|. This pin pivotally mounts an extension 62 of a member 63. The cylindrical portion 64 of this member has a transverse opening which receives one end of a pin 66. This pin is of substantial proportions and is carried by the turret Extending from the portion 64 is an arm 61 on the end of which is mounted a roller 68. This roller is adapted to contact the track l3 and guard For a clearer understanding of the invention, a complete cycle of operation of the mechanism of the invention is set out as follows; As shown in Fig. 1 of the drawings, the molding units, having their rollers 68 in contact with the portion 2'2 of the track, are in fully opened position, this position corresponding to the enlarged sectional view of Fig. 4. It will be noted that the molding elements 26 and 21 are in fully opened position, rod 5| is inclined to the direction of travel of shaft 33, and rollers 4| are at the bottom of the slots 42, the element 21 being turned as shown in Figs. 3 and 1. The molding unit, designated in Fig. l as A, has received a powder or pellet charge in the cavity 28 and, as the turret rotates, contact of roller 68 of this unit with the vertical portion |'6 of the track causes rotation of the member 63 and upward movement of rod 5|, shaft 33, and element 21. As upward movement of these parts continues, spring 31 compresses to an extent to allow movement of the rollers 4| to the upper ends of slots 42, this travel of the rollers being translated into slight rotary movement of the element 21 from the position shown in Fig. '7 to that of Fig. 5. When the roller 68 has moved onto the inclined portion H of the track, the parts are in the position shown in Fig. 2. Movement of the roller 68 along the uppermost portion ofincline |1 actuates parts 58 and 63 in a manner to cause spring 51 to constltutean active force by which to hold the mold elements 26 and 21 in proper position throughout a molding operation.

As heretofore brought out, difficulty is invariably experienced in loosening a newly molded article from either or both elements of a mold, this being particularly a problem in the molding of internally threaded caps. Thus it is first necessary to break loose the cap from its adherence to the threaded force on which it has been formed. Continuing with the molding sequence, as the turret I l continues to revolve, the molding units successively reach a point where the roller 66 of each member 63 comes into contact with the guard 19. This contactwith the guard causes the member 63 to commence rotating about its pivot 66, past dead center, and spring 51 may now act as a force to separate the mold elements. However, since there is a yieldable connection between rod 36 and shaft 33 of element 21, initial release of the spring 51, by rotation of member 63 past dead center, does not first effect separation of the mold elements but, rather, allows lengthwise movement as between rod 36 and shaft 33. This movement is in a direction such that rollers 4|, under the expanding action of sprin 31, travel to the lower ends of slots 42, thus slightly rotating element 21; that is, from the position of Fig. 5 to that of Fig. 7. This clockwise rotation, while the elements 26 and 21 are still in abutment, causes the mold piece within the cavity 28 to rotate slightly about the threads 3| of the force 29, thus loosening the article on the force. At this point the roller 68 rapidly moves down the inclined surface l3 of the track, further rotating member 63 and allowing spring 51 to fully separate the mold elements. Inasmuch as the mold elements are now separated, the molded article exposed to view and only loosely carried by the force 29, any suitable means, such as a revolving wheel, may be moved into engagement with the article to completely unthread it from the force.

Although applicant has shown and described only one form of his invention in connection with loosening molded articles preparatory to their removal from one or another of the mold elements, it will be understood that variations or modifications of the structure herein shown and described may be made and are contemplated insofar as they are within the spirit and scope of the invention as embodied in the annexed claims.

Having thus set forth my invention, what I claim as new and for which I desire protection by Letters Patent is:

1. In a molding machine having a rotatable turret, a plurality of molds carried by said turret, each of said molds comprising a fixed element and a cooperative movable element, a track on a stationary part of said machine, means for moving said movable element, said means being carried by said turret and rendered movable by engagement with at least a portion of said track, lost motion means connecting the movable element with said moving means, said lost motion means including two relatively movable parts constructed to turn said movable element about an axis common to both elements during relative movement of said last named parts.

2. In a molding machine, a mold comprising a pair of cooperative elements, one of said elements being fixed and the other movable, operable means for efiecting movement of the movable element toward or away from the fixed element to eifect closing and opening said mold, a lost motion connector between the movable element and said operable means, said connector including cooperative parts adapted to have such relative movement, during movement of said movable element, as to turn said movable element about an axis common to both elements.

3. In a molding machine having a rotatable turret, a plurality of molds carried by said turret, each of said molds comprising a fixed element and a cooperative movable element, a track on a stationary part of said machine, means for moving said movable element, said means being carried by said turret and rendered movable by engagement with at least a portion of said track, lost motion means connecting the movable element with said moving means, said lost motion means including parts so constructed and organized as to have relative movement to turn said movable element about an axis common to both elements during initial movement of said lost motion means and prior to relative movement of said elements.

4. In a moldin machine, a mold comprising a pair of cooperative mold elements relatively movable in the direction of their common axis into opened or closed position, operable means for effecting movement of said elements into colsed position, lost motion means associating at least one of the elements with said operable means, said lost motion means including relatively movable parts so constructed that, upon final movement of said operable means, to close said mold, said elements will relatively rotate about their common axis during relative movement of said movable parts.

5. In a moldin machine, a mold comprising a pair of cooperative elements, operable means for moving one of said elements toward or away from the other of said elements to eilect closing and opening said mold, lost motion means connecting the movable element with said operable means, said lost motion means including cooperative parts constructed to have such relative movement as to rotate the movable element about a center common to both elements during initial movement of said operable means in a direction to open Said mold and, during final movement of said operable means, in a direction to close said mold.

DAVID CROPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,959,612 Burke May 22, 1934 2,238,198 Weber Apr. 15, 1941 2,295,220 Kaula Sept. 8, 1942 2,306,205 Crosman, Jr Dec. 22, 1942 2,317,823 Strauss Apr. 27, 1943 

